1. Field of the Invention
This invention relates generally to semiconductor fabrication technology, and, more particularly, to a method and apparatus for scheduling execution of a controller based upon an impending lot arrival at a processing tool in an Advanced Process Control (APC) framework in a semiconductor fabrication environment.
2. Description of the Related Art
There is a constant drive in the semiconductor industry to increase the quality, reliability, and throughput of integrated circuit devices such as microprocessors, memory devices, and the like. This drive is fueled by consumer demands for higher quality computers and electronic devices that operate more reliably.
These demands by the consumer have resulted in some improvements in the manufacture of semiconductor devices as well as in the manufacture of integrated circuit devices incorporating such semiconductor devices. Reducing defects in the manufacture of these devices lowers the cost of the devices themselves. Accordingly, the cost of the final product incorporating these devices is also reduced, thus providing inherent monetary benefits to both the consumer and manufacturer.
Typically, several lots of wafers that are to be processed by a processing tool of the semiconductor manufacturing system are stored in a remote location from the processing tool, such as a wafer storage facility, for example. A manufacturing execution system (MES) will determine which of a particular lot of wafers needs to be processed by the processing tool subsequent to the tool running a current lot of wafers. When the desired lot of wafers is retrieved from the remote storage facility and delivered to the processing tool, the manufacturing execution system will have xe2x80x9crecipe calculationsxe2x80x9d performed for the processing tool to run the desired lot of wafers retrieved from the remote storage facility. While these recipe calculations are being performed, the processing tool will remain idle until the recipe calculations are made. In some cases, the processing tool may remain idle for a period of sixty seconds, if not longer, as it awaits the recipe calculations to run the desired lot of wafers. The longer the processing tool remains idle while awaiting the recipe calculations, the greater the loss of productivity by the processing tool, which may adversely impact the overall operational costs associated with the semiconductor manufacturing system.
The present invention is directed to overcoming, or at least reducing the effects of, one or more of the problems set forth above.
In one aspect of the present invention, a method is provided. The method comprises determining a lot of processing pieces that is to be processed by a processing tool and retrieving the lot of processing pieces from a remote location. A predefined set of calculations is initiated relating to the operation of the processing tool in anticipation of delivering the lot of processing pieces to the processing tool. The lot of processing pieces is delivered to the processing tool, and the processing pieces are processed by the processing tool using the predefined set of calculations.
In another aspect of the present invention, a system is provided. The system comprises a processing tool adapted to process a lot of processing pieces and a first controller adapted to retrieve the lot of processing pieces from a remote location. A second controller is provided and adapted to control the processing tool and to determine the lot of processing pieces that is to be processed by the processing tool. The system also includes a third controller adapted to perform a predefined set of calculations relating to the operation of the processing tool, wherein the third controller initiates performance of the predefined set of calculations prior to receipt of the lot of processing pieces at the processing tool. The processing tool is further adapted to process the processing pieces using the predefined set of calculations in response to the processing pieces being delivered to the processing tool.